_April 15, 2013: At least 36 are killed in string of attacks across the country ahead of provincial elections.

_April 6, 2013: A suicide bomber blows himself up at a lunch hosted by a Sunni candidate ahead of regional elections, killing 20 people.

_Mar. 19, 2013: Insurgents carry out a wave of bombings that kills at least 65 people on the eve of the 10th anniversary of the U.S.-led invasion. An al-Qaida in Iraq front group claims responsibility.

_April 19, 2012: Bombs rip through 10 Iraqi cities, killing at least 30 and shattering a month of relative calm. Al-Qaida later says the attacks aimed to punish the Shiite-led government and its allies.

_March 20, 2012: Insurgents bent on derailing an Arab League meeting in Baghdad kill 46 in attacks on Shiite pilgrims in the holy city of Karbala, bombings in Kirkuk, and strikes on security and government officials around the country.

_Feb. 23, 2012: Attackers kill at least 55 as car bombs go off near an elementary school in the town of Musayyib, a restaurant in a Shiite neighborhood in Baghdad, and various checkpoints and secure areas.